Computer Knowledge

Java Core Classes and Threads

1,935 Questions

Java core classes and threads form the foundation of object oriented programming and are crucial for IT officer and programming exams. This includes concepts like string mutability, collections, and multithreading. Solve these questions to test your practical coding and theoretical knowledge.

String and StringBuffer classesThread execution methodsJava collections frameworkCharacter streams input outputVariable serialization rules

Java Core Classes and Threads Questions

Multiple choice

Which of the following statements are true?

  1. The Iterator interface declares only three methods: hasNext, next and remove.
  2. The ListIterator interface extends both the List and Iterator interfaces.
  3. The ListIterator interface provides forward and backward iteration capabilities.
  4. The ListIterator interface provides the ability to modify the List during iteration.
  5. The ListIterator interface provides the ability to determine its position in the List.

  1. 2, 3, 4 and 5

  2. 1, 3, 4 and 5

  3. 3, 4 and 5

  4. 1, 2 and 3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The ListIterator interface extends the Iterator interface and declares additional methods to provide forward and backward iteration capabilities, List modification capabilities and the ability to determine the position of the Iterator in the List.

Multiple choice

Which of the following statements is false regarding 'finally' keyword in Java?

  1. Finally block does not get executed in case an exception does not occur.

  2. There can be multiple finally blocks in a Java method.

  3. Finally block is optional.

  4. A try statement without a catch block must be followed by a finally block.

  5. The finally block executes even if no catch block executes.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct answer. The given statement is false. The finally block executes even if an exception does not occur.